that lance armstrong did not want to be a participant in any dealmaking. and he got scared. >> reporter: coming clean to authorities isn't like talking to oprah. >> did you ever take banned substances to enhance your cycling performance? >> yes. >> reporter: armstrong will have to do what he's fought hard to avoid. testifying under oath with perjury charges at stake. the testimony could take days and will require armstrong to provide substantial assistance to investigators. meaning, he must name names, who helped him get the drugs. who helped him hide and transport them. pass the drug tests and keep the secret hidden for so long. he'll essentially have to roll over on people he seemed interested in protecting. >> planet armstrong is a dark and lonely place right now. he's got major problems. >> reporter: a pile of civil lawsuits are active, as well. including a class-action suit by people who bought armstrong's best-selling books. defendants knew or should have known these were fiction. u.s. doping authorities have given armstrong a two-week window to come